Pesticide Monitoring in Streams
Surface water from nine rivers is sampled under the Pesticide Monitoring Program. Three of the nine rivers are sampled each year for a selected number of pesticides.
Stream water samples and sediment samples are collected once in July, twice in August (once during a normal/dry weather and once during wet weather), and once in September. The two samples in July and September are collected during dry weather. Department staff collect the samples, which are then sent to the same laboratory as the drinking water samples.
At each of the three sites, tissue samples are also collected once a year for finfish (brook or rainbow trout) and shellfish (soft shell clams and mussels).
Sediment sampling involves collecting sediment from the stream floor at the same location as the stream water sampling is conducted. The first sediment samples were collected in 2014 in an attempt to determine whether pesticide residues are present, as other sampling found sediments can contain pesticide residues.
Finfish are collected from the same river systems where the stream water monitoring occurs either by electrofishing and rod and reel. Shellfish were collected from the same stream systems manually. The samples are collected as close to the stream water sampling sites as possible, with the purpose of the sampling to determine if pesticide residues accumulate in the fish/shellfish.
What resources are available?
A summary document, which displays each detected pesticide and its safe stream water limit in a graph format can be downloaded from the resources listed on the right. A similar document also displays pesticide detections in finfish showing a Health Canada General Maximum Residue Limit for human consumption. The charts show that all of the pesticide compounds detected are at levels below their respective water quality limits.
There have been no detections found in the sediment samples. A map of the sampling sites is also available for download. Open data on Stream Water Sampling, Stream Sediment Sampling, Finfish and Shellfish Sampling are available on the Online Services section of this website.